Early follicular use of long-acting analogues of gonadotrophin releasing hormone (GnRH) in IVF programmes has caused some concern with respect to its teratogenic potential. In the case reported here, an injection of DTRP6 GnRH microcapsules was given in the 5th week of a spontaneous unsuspected pregnancy. No deleterious effect or teratogenesis of the embryo could be demonstrated at birth or 18 months later.